Echinacea - Plavix (Clopidogrel) Interaction

Interaction Details

Clopidogrel is classified as belonging to the following category: Cytochrome P450 1A2 (Cyp1A2) Substrates

Echinacea might inhibit the metabolism of CYP1A2 and increase plasma levels of some drugs.
Echinacea appears to inhibit CYP1A2 enzymes in humans. Additionally, echinacea seems to increase plasma concentrations of caffeine, a CYP1A2 substrate, by around 30%. Theoretically, echinacea might increase levels of other drugs metabolized by CYP1A2.

Interaction Rating

Likelihood of Occurrence

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists

Pharmacist Analysis

The potential interaction between Plavix (clopidogrel) and echinacea is not well understood in terms of its clinical significance.

Plavix is primarily metabolized by the liver enzyme CYP2C19, with minor contributions from CYP3A4, CYP2B6, and CYP1A2.

Echinacea has been shown to inhibit CYP3A4 and CYP1A2 to varying degrees. While the majority of Plavix is metabolized by CYP2C19, changes to these other enzymes could theoretically impact the concentration of the drug in the blood, potentially increasing the risk of side effects.

There haven't been any human studies evaluating the effects of combining these two substances, so the seriousness of this interaction is not known. However, out of caution, it is recommended that the combination only be used under the supervision of a healthcare provider to ensure appropriate monitoring.

References

• Gorski JC, Huang S, Zaheer NA, et al. The effect of echinacea (Echinacea purpurea root) on cytochrome P450 activity in vivo.Clin Pharmacol Ther 2003;73 (Abstract PDII-A-8):P94.

Interaction Details

Clopidogrel is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Substrates

Echinacea may induce hepatic CYP3A4 and inhibit intestinal CYP3A4. This may increase or decrease levels of drugs metabolized by CYP3A4.
Several clinical trials have shown that taking echinacea for up to one month does not significantly affect the metabolism of various CYP3A4 substrates, including midazolam, docetaxel, etravirine, lopinavir-ritonavir, and darunavir-ritonavir. However, other clinical research shows that echinacea may increase the clearance of midazolam, suggesting that echinacea might induce CYP3A4. The discrepancy is thought to be due to differing effects of echinacea on intestinal versus hepatic CYP3A4 enzymes. Echinacea appears to induce hepatic CYP3A4 but inhibit intestinal CYP3A4. In some cases, these effects might cancel each other out, but in others, drug levels may be increased or decreased depending on the level of effect at hepatic and intestinal sites. The effect of echinacea on CYP3A4 activity may differ depending on the CYP3A4 substrate.

Interaction Rating

Likelihood of Occurrence

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists

Pharmacist Analysis

The potential interaction between Plavix (clopidogrel) and echinacea is not well understood in terms of its clinical significance.

Plavix is primarily metabolized by the liver enzyme CYP2C19, with minor contributions from CYP3A4, CYP2B6, and CYP1A2.

Echinacea has been shown to inhibit CYP3A4 and CYP1A2 to varying degrees. While the majority of Plavix is metabolized by CYP2C19, changes to these other enzymes could theoretically impact the concentration of the drug in the blood, potentially increasing the risk of side effects.

There haven't been any human studies evaluating the effects of combining these two substances, so the seriousness of this interaction is not known. However, out of caution, it is recommended that the combination only be used under the supervision of a healthcare provider to ensure appropriate monitoring.

References

• Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82.
• Yale SH, Glurich I. Analysis of the inhibitory potential of Ginkgo biloba, Echinacea purpurea, and Serenoa repens on the metabolic activity of cytochrome P450 3A4, 2D6, and 2C9. J Altern Complement Med 2005;11:433-9.
• Gorski JC, Huang S, Zaheer NA, et al. The effect of echinacea (Echinacea purpurea root) on cytochrome P450 activity in vivo.Clin Pharmacol Ther 2003;73 (Abstract PDII-A-8):P94.
• Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo assessment of botanical supplementation on human cytochrome P450 phenotypes: Citrus aurantium, Echinacea purpurea, milk thistle, and saw palmetto. Clin Pharmacol Ther 2004;76:428-40. .
• Penzak, S. R., Robertson, S. M., Hunt, J. D., Chairez, C., Malati, C. Y., Alfaro, R. M., Stevenson, J. M., and Kovacs, J. A. Echinacea purpurea significantly induces cytochrome P450 3A activity but does not alter lopinavir-ritonavir exposure in healthy s
• Schroder-Aasen T, Molden G, Nilsen OG. In vitro inhibition of CYP3A4 by the multiherbal commercial product Sambucus Force and its main constituents Echinacea purpurea and Sambucus nigra. Phytother Res 2012;26(11):1606-13.
• Goey AK, Meijerman I, Rosing H, et al. The effect of Echinacea purpurea on the pharmacokinetics of docetaxel. Br J Clin Pharmacol 2013;76(3):467-74.
• Moltó J, Valle M, Miranda C, et al. Herb-drug interaction between Echinacea purpurea and etravirine in HIV-infected patients. Antimicrob Agents Chemother 2012;56(10):5328-31.
• Hansen TS, Nilsen OG. In vitro CYP3A4 metabolism: inhibition by Echinacea purpurea and choice of substrate for the evaluation of herbal inhibition. Basic Clin Pharmacol Toxicol 2008;103:445-9.

Clopidogrel Overview

• Clopidogrel is used alone or with aspirin to prevent serious or life-threatening problems with the heart and blood vessels in people who have had a stroke, heart attack, or severe chest pain. This includes people who have percutaneous coronary intervention (PCI; angioplasty; a type of heart surgery) that may involve inserting coronary stents (metal tubes surgically placed in clogged blood vessels to improve blood flow) or who have coronary artery bypass grafting (CABG; a type of heart surgery). Clopidogrel is also used to prevent serious or life-threatening problems with the heart and blood vessels in people who have peripheral arterial disease (poor circulation in the blood vessels that supply blood to the legs). Clopidogrel is in a class of medications called antiplatelet medications. It works by preventing platelets (a type of blood cell) from collecting and forming clots that may cause a heart attack or stroke.

Echinacea - More Interactions

Echinacea interacts with 787 drugs

Interaction Rating Key

These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.